<?php
/**
 * CActiveDataProvider class file.
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @link http://www.yiiframework.com/
 * @copyright 2008-2013 Yii Software LLC
 * @license http://www.yiiframework.com/license/
 */

/**
 * CActiveDataProvider implements a data provider based on ActiveRecord.
 *
 * CActiveDataProvider provides data in terms of ActiveRecord objects which are
 * of class {@link modelClass}. It uses the AR {@link CActiveRecord::findAll} method
 * to retrieve the data from database. The {@link criteria} property can be used to
 * specify various query options.
 *
 * CActiveDataProvider may be used in the following way:
 * <pre>
 * $dataProvider=new CActiveDataProvider('Post', array(
 *     'criteria'=>array(
 *         'condition'=>'status=1',
 *         'order'=>'create_time DESC',
 *         'with'=>array('author'),
 *     ),
 *     'countCriteria'=>array(
 *         'condition'=>'status=1',
 *         // 'order' and 'with' clauses have no meaning for the count query
 *     ),
 *     'pagination'=>array(
 *         'pageSize'=>20,
 *     ),
 * ));
 * // $dataProvider->getData() will return a list of Post objects
 * </pre>
 *
 * @property CDbCriteria $criteria The query criteria.
 * @property CDbCriteria $countCriteria The count query criteria. This property is available
 * since 1.1.14
 * @property CSort $sort The sorting object. If this is false, it means the sorting is disabled.
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @package system.web
 * @since 1.1
 */
class CActiveDataProvider extends CDataProvider
{
    /**
     * @var string the primary ActiveRecord class name. The {@link getData()} method
     * will return a list of objects of this class.
     */
    public $modelClass;
    /**
     * @var CActiveRecord the AR finder instance (eg <code>Post::model()</code>).
     * This property can be set by passing the finder instance as the first parameter
     * to the constructor. For example, <code>Post::model()->published()</code>.
     * @since 1.1.3
     */
    public $model;
    /**
     * @var string the name of key attribute for {@link modelClass}. If not set,
     * it means the primary key of the corresponding database table will be used.
     */
    public $keyAttribute;

    /**
     * @var CDbCriteria
     */
    private $_criteria;
    /**
     * @var CDbCriteria
     */
    private $_countCriteria;

    /**
     * Constructor.
     * @param mixed $modelClass the model class (e.g. 'Post') or the model finder instance
     * (e.g. <code>Post::model()</code>, <code>Post::model()->published()</code>).
     * @param array $config configuration (name=>value) to be applied as the initial property values of this class.
     */
    public function __construct($modelClass, $config = array())
    {
        if (is_string($modelClass)) {
            $this->modelClass = $modelClass;
            $this->model = $this->getModel($this->modelClass);
        } elseif ($modelClass instanceof CActiveRecord) {
            $this->modelClass = get_class($modelClass);
            $this->model = $modelClass;
        }
        $this->setId(CHtml::modelName($this->model));
        foreach ($config as $key => $value)
            $this->$key = $value;
    }

    /**
     * Returns the query criteria.
     * @return CDbCriteria the query criteria
     */
    public function getCriteria()
    {
        if ($this->_criteria === null)
            $this->_criteria = new CDbCriteria;
        return $this->_criteria;
    }

    /**
     * Sets the query criteria.
     * @param CDbCriteria|array $value the query criteria. This can be either a CDbCriteria object or an array
     * representing the query criteria.
     */
    public function setCriteria($value)
    {
        $this->_criteria = $value instanceof CDbCriteria ? $value : new CDbCriteria($value);
    }

    /**
     * Returns the count query criteria.
     * @return CDbCriteria the count query criteria.
     * @since 1.1.14
     */
    public function getCountCriteria()
    {
        if ($this->_countCriteria === null)
            return $this->getCriteria();
        return $this->_countCriteria;
    }

    /**
     * Sets the count query criteria.
     * @param CDbCriteria|array $value the count query criteria. This can be either a CDbCriteria object
     * or an array representing the query criteria.
     * @since 1.1.14
     */
    public function setCountCriteria($value)
    {
        $this->_countCriteria = $value instanceof CDbCriteria ? $value : new CDbCriteria($value);
    }

    /**
     * Returns the sorting object.
     * @param string $className the sorting object class name. Parameter is available since version 1.1.13.
     * @return CSort the sorting object. If this is false, it means the sorting is disabled.
     */
    public function getSort($className = 'CSort')
    {
        if (($sort = parent::getSort($className)) !== false)
            $sort->modelClass = $this->modelClass;
        return $sort;
    }

    /**
     * Given active record class name returns new model instance.
     *
     * @param string $className active record class name.
     * @return CActiveRecord active record model instance.
     *
     * @since 1.1.14
     */
    protected function getModel($className)
    {
        return CActiveRecord::model($className);
    }

    /**
     * Fetches the data from the persistent data storage.
     * @return array list of data items
     */
    protected function fetchData()
    {
        $criteria = clone $this->getCriteria();

        if (($pagination = $this->getPagination()) !== false) {
            $pagination->setItemCount($this->getTotalItemCount());
            $pagination->applyLimit($criteria);
        }

        $baseCriteria = $this->model->getDbCriteria(false);

        if (($sort = $this->getSort()) !== false) {
            // set model criteria so that CSort can use its table alias setting
            if ($baseCriteria !== null) {
                $c = clone $baseCriteria;
                $c->mergeWith($criteria);
                $this->model->setDbCriteria($c);
            } else
                $this->model->setDbCriteria($criteria);
            $sort->applyOrder($criteria);
        }

        $this->model->setDbCriteria($baseCriteria !== null ? clone $baseCriteria : null);
        $data = $this->model->findAll($criteria);
        $this->model->setDbCriteria($baseCriteria); // restore original criteria
        return $data;
    }

    /**
     * Fetches the data item keys from the persistent data storage.
     * @return array list of data item keys.
     */
    protected function fetchKeys()
    {
        $keys = array();
        foreach ($this->getData() as $i => $data) {
            $key = $this->keyAttribute === null ? $data->getPrimaryKey() : $data->{$this->keyAttribute};
            $keys[$i] = is_array($key) ? implode(',', $key) : $key;
        }
        return $keys;
    }

    /**
     * Calculates the total number of data items.
     * @return integer the total number of data items.
     */
    protected function calculateTotalItemCount()
    {
        $baseCriteria = $this->model->getDbCriteria(false);
        if ($baseCriteria !== null)
            $baseCriteria = clone $baseCriteria;
        $count = $this->model->count($this->getCountCriteria());
        $this->model->setDbCriteria($baseCriteria);
        return $count;
    }
}
